We remember the 20th century because we've all lived in some part of it (unless of course a 9 year older is reading this) and seen lots of video about it. The century was well covered by modern media. We know less of the 19th century and some of its major natural events are not widely known.

As compared to the 19th century the 20th century was pretty calm from the standpoint of big natural changes. What I'm going to do with this post: Imagine that the 21st century turns out to be like the 19th century in terms of the severity of climate, volcanic, and other natural events.

How do we start out? Well, I'm going to ignore the Little Ice Age that spanned centuries and didn't end until 1850 because obviously we aren't already in a mini Ice Age. So lets start with the first big unique natural event of the 19th century.

A geologically calamitous 21 century might start with an earthquake on December 2011 along the Mississippi river in the center of the United States. That would be the equivalent to the December 16, 1811 New Madrid earthquake that began a series of 8.1 and 8.2 earthquakes over a period of a few months that would cause rivers to run backward, the Mississippi to change course (with far more calamitous results given much higher population densities) and church bells would again ring as far away as Boston. Picture bridges across the Mississippi collapsing with freight trains halted and river freight shipping blocked. A repeat of the New Madrid Missouri earthquakes would cause far more devastating damage than when that area was sparsely populated and the Mississippi was not used to move huge amounts of agricultural and other freight.

An earthquake in the middle of the US would be far more devastating than one on the US West Coast for two reasons. First off, cities like Memphis were not built to California earthquake standards. Second, the soil along the Mississippi can flow and send shock waves much greater distances. The area of devastation would therefore be much larger.

What next? A VEI (Volcanic Explosivity Index) 7 volcano. Likely location: Indonesia. Now the 4th most populated country in the world. On April 10th 1815 Mount Tambora erupted with VEI 7 intensity.. The eruption so reduced solar radiation reaching the surface that snow fell in New England and the Canadian Maritime provinces in June. You can imagine what that did to crop yields. People went hungry, causing the biggest famine of the 19th century. And get this: 1816 had even worse cold weather and bigger crop failures. So imagine 2015 and 2016 with worldwide crop failures in a world with 7 billion people, all due to a very plausible VEI 7 volcanic eruption.

What would 2016 be like? Food prices would be very high, too high for the poorest to afford. We'd see civil unrest and rioting in many nations. Revolutions would be likely. The cold weather would increase demand for heating oil, natural gas, coal, and wood for heating. So energy commodity prices would soar along with agricultural commodities. Many countries (possibly including the United States) would ban the export of grains.

No doubt 1815 and 1816 were difficult years for many other mammalian species as well. But a VEI 7 eruption in the early 21st century would cause much bigger problems for orangutans, gorillas, big cats, and other threatened species for a couple of reasons. First off, their numbers have already fallen in the last couple of centuries by orders of magnitude. So they already are living close to the edge of extinction. Pretty small disruptions to their food supply run much greater risks of wiping them out. Second, with much larger numbers of humans living near them now they face much greater risk of being hunted to extinction by hungry humans.

So at least one big earthquake and a pretty big volcano with two lost growing seasons. The century is still young. What's next? On September 2, 1859 an unusually large coronal mass ejection by the Sun cause intense magnetic fields on Earth which if they happened today would cause a large fraction of the big electric power transformers to fail in large electric grids. Large areas of industrialized countries would be without electric power for months. Picture cities evacuated due to lack of power to operate water pumps. Picture massive computer server farms sitting dark. Banks would fail.

The 19th century also featured a VEI 6 volcano, the well known Krakatoa eruption in 1883. This wasn't as severe as the 1815 eruption. But it would cause a global cooling and crop losses.

The 20th century was a relatively mild, wet, and calm century as compared to the 19th century. We would make a mistake to expect the 21st century will be as calm as the 20th. The current low level of sun spot activity could continue and we could go thru a cooler period in spite of our CO2 emissions. Or we could have severe cooling periods caused by large volcanic eruptions. Also, earthquakes could hit major cities or cause tsunami damage. Do not be shocked if a severe turn of events happens. Even the early 20th century had a dramatic event in 1908 with the Tunguska asteroid explosion over a large swath of Siberia.

But would Man have been able to afford those 2 huge world wars with a summer like 1816? And some of the other events Randall describes? Would they have been necessary or possible if famine wiped out larger numbers of human males in Europe, North America and East Asia?

couple of cities knocked down by earthquakes is no big deal (there were a few such in the 20th century, e.g. "Great Kantou" 1923, Asgabat 1947, Managua 1972, Tangshan 1976 etc). As long as nothing drastic enough happens with the climate to damage the food production significantly for many years in a row, it's the politics and wars that is capable of truly major damage. Come to think of it, we are now witnessing American economy falling apart without a single earthquake or other disaster happening, just through the run-of-the-mill process of politics and business management over here and over there in Asia. Russia fell apart economically in late 80s likewise without any disasters, just "in the course of human events". Those human events sure can wreck havoc when mismanaged sufficiently.

Your post reminds me of Heinlein's "Year of the Jackpot," an end-of-the-world story in which a statistician realizes that all the negative trend lines--social, economic, climatic, and so on--are about to converge on a single point in time.

The point of my post is to get across the idea that we can't generalize about the future based on recent events. Just go back another hundred years and what's considered to be normal events from Mother Nature look quite different. People expect the future not to be radically different. There's a pretty decent chance they are wrong.

Michael L,

New Madrid's earthquakes are important because they are not just about one city getting whacked. An earthquake in a non-rocky area with a major river is a completely different game. An earthquake that can ring church bells 1200 miles away is a different kettle of fish. Not all earthquakes are only local in effects.

Although I generally like this site, the author sometimes veers off into views that really aren't supported by science.

For example, his cursory reference to the :Little Ice Age" is a good place to start. The science behind such a claim that there actually was a literal "Little Ice Age" during the periods mentioned is far from an established claim. It's funny that the author of this site calls into question human caused global warming but readily accepts claims of a "Little Ice Age" when these claims are tenuous at best.

There are some 10-months-pregnant earthquake faults running through the Carolinas as well. As I recall, Charleston is at huge risk, and just like Memphis has building codes that are deficient with regard to seismicity.

Food shortages and/or natural disasters have the potential to create all sorts of political friction. Suppose LA gets leveled by the "big one." How much of the rest of the country will give a rat's ass? Not many, I'm afraid. There might even be some who would suggest that the occasion of LA's desctruction would be the opportune time to just quit claim it back to the Mexicans: "There. You've been whining and pissing and moaning about it for 150 years. Guess what? It's yours now." Of course, handing Mexico City a smoldering pile of bricks would be "racist."

If I've veered off into views of the Little Ice Age that are not supported by science at least I've done so in the company of a lot of scientists. It is not hard to find lots of scientific reports from big name universities of scientists reporting on findings they've made about this mythical age. For example, from Stanford in 2008:

Stanford University researchers have conducted a comprehensive analysis of data detailing the amount of charcoal contained in soils and lake sediments at the sites of both pre-Columbian population centers in the Americas and in sparsely populated surrounding regions. They concluded that reforestation of agricultural lands—abandoned as the population collapsed—pulled so much carbon out of the atmosphere that it helped trigger a period of global cooling, at its most intense from approximately 1500 to 1750, known as the Little Ice Age.

"We estimate that the amount of carbon sequestered in the growing forests was about 10 to 50 percent of the total carbon that would have needed to come out of the atmosphere and oceans at that time to account for the observed changes in carbon dioxide concentrations," said Richard Nevle, visiting scholar in the Department of Geological and Environmental Sciences at Stanford. Nevle and Dennis Bird, professor in geological and environmental sciences, presented their study at the annual meeting of the American Geophysical Union on Dec. 17, 2008.

Nevle and Bird synthesized published data from charcoal records from 15 sediment cores extracted from lakes, soil samples from 17 population centers and 18 sites from the surrounding areas in Central and South America. They examined samples dating back 5,000 years.

What they found was a record of slowly increasing charcoal deposits, indicating increasing burning of forestland to convert it to cropland, as agricultural practices spread among the human population—until around 500 years ago: At that point, there was a precipitous drop in the amount of charcoal in the samples, coinciding with the precipitous drop in the human population in the Americas.

DURHAM, N.H. – A new study that reports precise ages for glacial moraines in southern Peru links climate swings in the tropics to those of Europe and North America during the Little Ice Age approximately 150 to 350 years ago. The study, published this week in the journal “Science”, “brings us one step closer to understanding global-scale patterns of glacier activity and climate during the Little Ice Age,” says lead author Joe Licciardi, associate professor of Earth sciences at the University of New Hampshire. “The more we know about our recent climate past, the better we can understand our modern and future climate.”

The study, “Holocene glacier fluctuations in the Peruvian Andes indicate northern climate linkages,” was borne of a convergence of a methodological breakthrough in geochronological techniques and Licciardi’s chance encounter with well-preserved glacial moraines in Peru.

If some revisionists are claiming there was no Little Ice Age then they seem to be on the fringe so far.

What's missing from this analysis is how typical the 19th century was. Implicit in the statement "The 20th century was a relatively mild, wet, and calm century as compared to the 19th century. We would make a mistake to expect the 21st century will be as calm as the 20th." is the idea that the 19th century was more "normal" than the 20th. But do we know that for sure? How did the 19th century compare to the 18th century? The 17th? The 16th?

Based on everything that's written above, I could just as easily conclude that the 19th century was the aberration. More data, please.

Great theoretical post. I can't find the citation in question, but I remember reading something after the latest 7.0+ earthquake in Indonesia that the 2004 Christmas Eve megaquake was thought to have ushered in an active period of several large quakes in that region over the next, let's say, 50 years. This was backed up with geological evidence for a cycle that happens every 200 years or so. I'm sorry that I can't find the source. I've also seen reports that the "Big One" is predicted to hit the Parkfield/Cholame segment of the San Andreas fault as that's the area that's currently "locked" - meaning that it's the place most likely to experience a rupture in the next thirty years or so: http://www.sciencedaily.com/releases/2009/07/090709140817.htm

Matt: I guess the idea is that we know the 19th C, worldwide, much better than we know the 18th & before. Of course this is very rough, but at very least the message should be to include the last 200 years of data in your reckoning of how often bad things happen, rather than just the more familiar last 100.

"Suppose LA gets leveled by the 'big one.' How much of the rest of the country will give a rat's ass? Not many, I'm afraid."

Not many until they find their store shelves aren't stocked to the gills as they are now with Asian imports, which mostly pass through the massive ports of LA and Long Beach. Unless the Panama Canal has been widened to accommodate the huge container ships that bring in most of our daily goods, it would mean a major disruption to the ever important supply chain, especially for many US manufacturers that rely on just-in-time techniques (ie: zero inventories). A shortage of parts or raw materials could idle factories and cause shortages on store shelves throughout the country. In fact, this was the threat that many longshoremen held over the heads of the Ports during their last major strike.

Southern California recovered fairly quickly after the 1994 Northridge quake (magnitude 6.7) just as the Bay Area did after the 1989 Loma Prieta "World Series" Earthquake (magnitude 6.9). That said, Northridge racked up $20 billion in damage, and even in California, buildings are not expected to survive earthquakes above magnitude 8.0.

"There might even be some who would suggest that the occasion of LA's desctruction would be the opportune time to just quit claim it back to the Mexicans"

Really? You'd hand over several major Navy, Marine and Air Force installations just like that? And the nuclear power plant? I'm not sure what the Mexicans would want with Nixon's grave. Or Reagan's, if you include Simi Valley in your definition of "LA".

"Suppose LA gets leveled by the 'big one.' How much of the rest of the country will give a rat's ass? Not many, I'm afraid."

Randall,

Kudos for an excellent post on the complacency of perception, and as witnessed by the comment I quote above the extent to which few grasp the magnitude of what your post implies. To the commenter Tm above, i wonder what rock you live under. Beyond the wrenching pain most Americans would experience as much of the daily entertainment and reality shows emanating out of Hollywood disappeared from peoples TV screens and movie theaters. America is a country characterized by very high mobility and most Americans have friends, acquaintances and colleagues in every major conurbation, and would experience personal losses.

But, the greatest implications of what you are speaking of Randall in the LA or Mid west Earthquake example, and by extension the world, is the extraordinary level of integration of all our economic systems, and further more the leveraging of that integration in every possible way. The financial crises is a dry run for the ripple effects and feedback loops built deep into the massively integrated global system. Our highly leveraged economy would not easily absorb a massive California or Mississippi valley earthquake. The magnification of the financial crises around the world, is the ringing of "church bells" in modern context. Would a 8.0 quake destroying Bank of America's Charlotte HQ be similar to the collapse of Lehman brothers, with many financial players unable to gauge counter party risk exposures, leading to panic. How about those server farm gobbling solar flares erasing the information "lifeblood" of our modern world. It seems we are inevitably due for a trans-formative natural "event" that forces us to adopt a far more robust existence.